.calendar {
    border: 1px solid #eee;
    border-radius: 8px;
    padding: 16px;
    width: 300px;
    height: 250px;
    margin-bottom: 16px;
    box-shadow: #ccc 2px 2px 4px 1px;
    box-sizing: content-box;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 40px;
}

.days {
    display: flex;
    flex-wrap: wrap;
}

.empty,
.day {
    width: calc(100% / 7);
    text-align: center;
    line-height: 30px;
}

.day:hover {
    background-color: #ccc;
    cursor: pointer;
    border-radius: 6px;
}

.day:hover, .selected {
    background-color: #007acc;
    color: #fff;
    font-weight: bold;
    cursor: pointer;
    border-radius: 6px;
}